So much for safety risks; a new "flytrap" molecule has been discovered that literally gobbles up nuclear waste ions. (Source: Mercouri Kanatzidis / courtesy Argonne National Laboratory)

Molecule could be used to cleanup Chernobyl and make future plants even safer.

Mercouri
Kanatzidis, a scientist at the U.S. Department of Energy's
(DOE) Argonne National Laboratory,
and Nan Ding, a chemist at Northwestern University, have discovered a
little molecule that may make a big difference in the nuclear power
debate by making nuclear plants safer.

The molecule features a
bizarre mechanism in which it behaves like a Venus flytrap, closing
selectively on radioactive
ions. That's a big deal as few molecules in the past have
shown the potential to effectively and permanently isolate
radioactive particles.

The researchers were exploring ways to
trap radioactive cesium ions, a dangerous component of nuclear
waste water. Cesium radioactive isotopes typically have a
long half life meaning that if they are accidentally released they
decay slowly and pose a serious health risk. One cesium
isotope, Cesium-137, which has a half life of 30 years, has played a
critical role in maintaining dangerous levels of radioactivity in the
Chernobyl disaster zone. Residents of the region have
experienced higher cancer rates and incidences of other
problems.

That's why it's so exciting to find a molecule that
could potentially isolate those stray particles and allow them to be
filtered out of local water supplies -- finding the metaphorical
needle in a haystack.

Describes Professor
Kanatzidis, "The name of the game in cleaning up nuclear waste
is to concentrate the dangerous isotopes as efficiently as possible.
That's where this new material does its job."

The new
material is a rigid frame composed of negatively charged metal
sulfides. Its interior has a pore that attracts positively
charged ions. Non-radioactive sodium ions are freely attracted
inside the pore, and then interchanged with other sodium ions.
However, when radioactive cesium ions enter the pore, they get
stuck.

The researchers discovered the reason behind this.
Sodium, like most positively charged ions, attracts a shell of water
that helps to isolate it within the pore. Cesium, a large ion,
only weakly interacts with water, so it's relatively unprotected.
Sulfur atoms in the ring framework around the pore bind to the
cesium, changing the shape of the pore, much like a Venus flytrap
shutting on its prey.

Professor Kanatzidis elaborates,
"Imagine the framework like a Venus flytrap. When the
plant jaws are open, you can drop a pebble in and the plant won't
close—it knows it isn't food. When a fly enters, however, the
plant's jaws snap shut."

He adds, "As far as we
know, this Venus-flytrap process is unique. It also works over
a large range of acidities—an essential property for cleanup at
different sites around the world, where pH can range
considerably."

The research was published in
the prestigious journal Nature
Chemistry and
could lead to discoveries of similar flytrap molecules that could be
used to capture other radioactive ions.

Argonne National
Laboratory is funded by the U.S. Department of Energy, but is
privately managed by UChicago Argonne, LLC. President Barack
Obama has recently become a major
advocate of the U.S. adopting nuclear power, pushing for more
research grants and guaranteed loan funding for new plant
construction.

"Game reviewers fought each other to write the most glowing coverage possible for the powerhouse Sony, MS systems. Reviewers flipped coins to see who would review the Nintendo Wii. The losers got stuck with the job." -- Andy Marken